X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-relayd%2Fviewer-session.c;h=7a5bd6dca991e55d643477c58f763dbfc3e765be;hp=a4b859726a6ea9b9bc7ef86ac5a019f43e29bdc2;hb=664eef54fd79a523dc0674df806d155c9766a2d1;hpb=d62023be5fccac24ad404aff2915c1888c22755c

diff --git a/src/bin/lttng-relayd/viewer-session.c b/src/bin/lttng-relayd/viewer-session.c
index a4b859726..7a5bd6dca 100644
--- a/src/bin/lttng-relayd/viewer-session.c
+++ b/src/bin/lttng-relayd/viewer-session.c
@@ -41,25 +41,68 @@ end:
 	return vsession;
 }
 
+static int viewer_session_set_trace_chunk_copy(struct relay_viewer_session *vsession,
+		struct lttng_trace_chunk *relay_session_trace_chunk)
+{
+	int ret = 0;
+	struct lttng_trace_chunk *viewer_chunk;
+
+	assert(relay_session_trace_chunk);
+	assert(!vsession->current_trace_chunk);
+
+	DBG("Copying relay session's current trace chunk to the viewer session");
+	viewer_chunk = lttng_trace_chunk_copy(relay_session_trace_chunk);
+	if (!viewer_chunk) {
+		ERR("Failed to create a viewer trace chunk from the relay session's current chunk");
+		ret = -1;
+		goto end;
+	}
+
+	vsession->current_trace_chunk = viewer_chunk;
+end:
+	return ret;
+}
+
 /* The existence of session must be guaranteed by the caller. */
-int viewer_session_attach(struct relay_viewer_session *vsession,
+enum lttng_viewer_attach_return_code viewer_session_attach(
+		struct relay_viewer_session *vsession,
 		struct relay_session *session)
 {
-	int ret = 0;
+	enum lttng_viewer_attach_return_code viewer_attach_status =
+			LTTNG_VIEWER_ATTACH_OK;
+
+	ASSERT_LOCKED(session->lock);
 
 	/* Will not fail, as per the ownership guarantee. */
 	if (!session_get(session)) {
-		ret = -1;
+		viewer_attach_status = LTTNG_VIEWER_ATTACH_UNK;
 		goto end;
 	}
-	pthread_mutex_lock(&session->lock);
 	if (session->viewer_attached) {
-		ret = -1;
+		viewer_attach_status = LTTNG_VIEWER_ATTACH_ALREADY;
 	} else {
+		int ret;
+
+		assert(session->current_trace_chunk);
+		assert(!vsession->current_trace_chunk);
 		session->viewer_attached = true;
+
+		ret = viewer_session_set_trace_chunk_copy(vsession,
+				session->current_trace_chunk);
+		if (ret) {
+			/*
+			 * The live protocol does not define a generic error
+			 * value for the "attach" command. The "unknown"
+			 * status is used so that the viewer may handle this
+			 * failure as if the session didn't exist anymore.
+			 */
+			DBG("Failed to create a viewer trace chunk from the current trace chunk of session \"%s\", returning LTTNG_VIEWER_ATTACH_UNK",
+					session->session_name);
+			viewer_attach_status = LTTNG_VIEWER_ATTACH_UNK;
+		}
 	}
 
-	if (!ret) {
+	if (viewer_attach_status == LTTNG_VIEWER_ATTACH_OK) {
 		pthread_mutex_lock(&vsession->session_list_lock);
 		/* Ownership is transfered to the list. */
 		cds_list_add_rcu(&session->viewer_session_node,
@@ -69,10 +112,8 @@ int viewer_session_attach(struct relay_viewer_session *vsession,
 		/* Put our local ref. */
 		session_put(session);
 	}
-	/* Safe since we know the session exists. */
-	pthread_mutex_unlock(&session->lock);
 end:
-	return ret;
+	return viewer_attach_status;
 }
 
 /* The existence of session must be guaranteed by the caller. */
@@ -102,6 +143,7 @@ static int viewer_session_detach(struct relay_viewer_session *vsession,
 
 void viewer_session_destroy(struct relay_viewer_session *vsession)
 {
+	lttng_trace_chunk_put(vsession->current_trace_chunk);
 	free(vsession);
 }